Liquid atomizing devices

ABSTRACT

The invention relates to liquid atomizing devices, particularly intended for use in the burners of gas turbine engines. Such a device comprises a tubular body, through which, in use, air flows to a swirler formed by vanes at the downstream end of the body. The body is mounted on a support which contains a fluid passage communicating with a similar passage within the body. The fluid passage within the body is defined by a tubular member within the body and the passage may lie either within this member or between the member and the body wall. The fluid passage within the body terminates in an end wall within which, or adjacent to which, are a plurality of holes through which fluid is ejected downstream of the swirler and in a direction generally transverse to the airflow. The transverse direction of fluid ejection is achieved either by the directions of the holes themselves or by directing the fluid against a projection of the end wall or of the body. The tubular member may form part of the body or may conveniently be in the form of a cast insert. Preferably there are the same number of holes and vanes, and each hole is adjacent the root of an associated blade at the trailing edge thereof.

llnite States Patent [72] Inventors li-llarold Place Accringtnn; Alan G. Chwhire, hnrnley, both oil England [21] Appl. No. 839,902 [22] Filed July 6, 11969 [45] Patented Sept. 2%, 119711 [73] Assignee ,lnaeph Lucas (industries) Limited Birmingham, England [32] Priority July 18, 11963 [3 3] Great Britain [31] 34308/60 [54] LlQlUm ATOMKZIING DEVICES 8 Claims, 6 Drawing Figs.

[52] US. til 239/406, 239/418 [51] int. Cl B05b 7/10 [50] Field oi Search 239/399, 403, 405, 406, 418

[56] llteierencer Cited UNiTED STATES PATENTS 2,676,648 4/1954 Dennis et a]. 239/406 2,753,929 7/1956 Walshin 239/406 X 3,007,515 11/1961 Furdock 239/406 3,254,846 6/1966 Schreter et al.. 239/406 X 3,493,180 2/1970 Walsh ABSTRACT: The invention relates to liquid atomizing devices, particularly intended for use in the burners of gas turbine engines. Such a device comprises a tubular body, through which, in use, air flows to a swirler formed by vanes at the downstream end of the body. The body is mounted on a support which contains a fluid passage communicating with a similar passage within the body. The fluid passage within the body is defined by a tubular member within the body and the passage may lie either within this member or between the member and the body wall. The fluid passage within the body terminates in an end wall within which, or adjacent to which, are a plurality of holes through which fluid is ejected downstream of the swirler and in a direction generally transverse to the airflow. The transverse direction of fluid ejection is achieved either by the directions of the holes themselves or by directing the fluid against a projection of the end wall or of the body. The tubular member may form part of the body or may conveniently be in the form of a cast insert. Preferably there are the same number of holes and vanes, and each hole is adjacent the root of an associated blade at the trailing edge thereof.

SHEET 10F 5 3 6018 831 mama Sim 1971 PATENTEU SEP'28 lam SHEET W 0F 5 I I I /Y///////////////J N m an 3 km a wm 8% @w ATTOEN EYS LIQUID ATOMIZING DEVICES This invention relates to liquid atomizing devices particularly intended for use in the burners of gas turbine engines.

A liquid atomizing device in accordance with the invention comprises a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of said body and nozzle means arranged to inject liquid for atomization into the swirling airstream downstream of said swirler in a direction transverse to the airflow.

In the accompanying drawings FIGS. I to 7 are views, partially in longitudinal cross section, of six examples of the invention, FIGS. I, 3 and 4L being on a larger scale than the remainder, and FIG. 3 is a section on the line 33 in FIG. 4.

Referring firstly to the example of the invention shown in FIG. I the liquid atomizing device shown includes a tubular body of composite construction. The body is supported at one end by a support II through which there extends a liquid supply passage I2. At the other end of the body there is an air swirler 13 inside the tubular body to create a conically expanding airflow pattern immediately downstream of the body 10.

The liquid supply passage 12 is connected to one end of a tube I4 extending coaxially with the tubular body at the downstream end thereof but being bent at the opposite end to join said liquid supply passage. The tube 14b is connected to a hollow centerpiece 15 fitted inside the swirler I3. The centerpiece I5 has a closed wall at one end and adjacent this wall is formed with a series of liquid nozzles 16 through which liquid is ejected in use into the swirling airstream immediately downstream of the swirler 13. There are the same number of nozzles I6 as there are inclined blades on the swirler I3 and the nozzles 16 are associated respectively with the trailing edges of these blades, each nozzle being arranged adjacent the root of the associated blade, the trailing edge thereof being inclined to the radius along which liquid is ejected by the associated nozzle 16.

The arrangement shown in FIG. 2 is similar to that shown in FIG. I but instead of utilizing the radial nozzles I6 in a centerpiece 15 the tube M is fitted with a different centerpiece I7 incorporating a flange 13 onto which the liquid is directed by the inclined nozzles I9. The upstream face of the flange I6, which is of greater external diameter than the root diameter of the blades of the swirler I3, is of concave annular form arranged so that liquid impinging upon the concave annular face of the flange I3 is directed therefrom in an expanding sheet in a slightly upstream direction. In use, of course, the airflow through the tubular body I0 breaks up this expanding sheet substantially immediately after it has left the edge of the flange 13.

The device shown in FIG. 3 is similar in principle to that shown in FIG. I but is constructed in a different manner. The principal difference is that the tube I I is replaced by a cast insert 20 having a ring portion 21 at its upstream end joined to the central tube 22 by radial arms 23 through which liquid passages 24 extend.

The arrangement shown in FIGS. I and 8 is generally similar to that shown in FIG. 3, but has a cast insert 40 which includes a single liquid passage 41. The passage 41 lies within a radial arm 42 which has a diametrally opposed supporting web 43. The endpiece 15 is secured by welding to the insert I0. Each of the nozzles 16 is adjacent the root of a blade of the swirler I3 at the trailing edge thereof.

In the example shown in FIG. 5 there is no central tube M or central cast insert 26. Instead the body is constructed from inner and outer sleeves 25, 26 respectively, defining between them an annular passage 27 communicating with the liquid supply passage 12. This passage 27 terminates at an annular end wall 28 in which axially extending nozzles 29 are formed. The downstream end of the body has an inwardly directed annular rib 30 onto which liquid ejected by the nozzles 29 impinges before being carried away by the swirling airflow downstream of the swirler 13.

In the arrangement shown in FIG. 6 the swirler 33 is enclosed within a convergent nozzle 341, but the arrangement is otherwise the same as that shown in FIG. 5.

Turning finally to FIG. 7 the annular passage 27 terminates in noules 35 arranged around the periphery of the downstream end of the body and directed inwardly across the swirler 13. Each nozzle is, in fact, arranged to produce a jet of liquid which will intersect the axis but which is inclined thereto.

All the above-described devices are intended to give proper atomization of liquid over a wide range of liquid pressures and airflow rates. This is of particular importance in the burners of gas turbine engines since very low fuel pressures and airflow rates are available during starting, but the same burners are required to operate efficiently at high pressures and high airflow rates during high speed running of the engine.

Having thus described our invention what we claim as new and desire to secure by Letters Patent. is:

I. A liquid atomizing device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid and nozzle means comprising a plurality of holes communicating with the said passage and arranged to inject liquid for atomization into the airstream downstream of the said swirler in a direction transverse to the airflow, each said hole being adjacent the root of an associated blade and being directed radially from the axis of the said body.

2. A liquid atomizing device as claimed in claim 1 in which the trailing edge of each blade is inclined to the normal to said axis.

3. A liquid atomizing device as claimed in claim I in which the tubular body is of composite construction and includes a transverse portion which acts as a support, the said passage extending through said transverse portion.

4!. A liquid atomizing device as claimed in claim 3 in which said passage is defined by a tubular member which is for at least part of its length coaxial with said body.

5. A liquid atomizing device as claimed in claim 4 in which said passage is within the tubular member and said holes are formed adjacent an end wall of the passage.

6. A liquid atomizing device as claimed in claim 5 in which the axes of said holes are substantially perpendicular to the axis of the body.

7. A liquid atomizing device as claimed in claim 4 in which said passage is defined between the tubular member and the body and said holes are formed adjacent an end wall of the passage.

8. A liquid atomizing device as claimed in claim 7 in which the axes of said holes are inclined to the normal to the axis of the body. 

1. A liquid atomizing device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid and nozzle means comprising a plurality of holes communicating with the said passage and arranged to inject liquid for atomization into the airstream downstream of the said swirler in a direction transverse to the airflow, each said hole being adjacent the root of an associated blade and being directed radially from the axis of the said body.
 2. A liquid atomizing device as claimed in claim 1 in which the trailing edge of each blade is inclined to the normal to said axis.
 3. A liquid atomizing device as claimed in claim 1 in which the tubular body is of composite construction and includes a transverse portion which acts as a support, the said passage extending through said transverse portion.
 4. A liquid atomizing device as claimed in claim 3 in which said passage is defined by a tubular member which is for at least part of its length coaxial with said body.
 5. A liquid atomizing device as claimed in claim 4 in which said passage is within the tubular member and said holes are formed adjacent an end wall of the passage.
 6. A liquid atomizing device as claimed in claim 5 in which the axes of said holes are substantially perpendicular to the axis of the body.
 7. A liquid atomizing device as claimed in claim 4 in which said passage is defined between the tubular member and the body and said holes are formed adjacent an end wall of the passage.
 8. A liquid atomizing device as claimed in claim 7 in which the axes of said holes are inclined to the normal to the axis of the body. 